From Wikipedia (http://en.wikipedia.org/wiki/Super_Robot_Wars):
Super Robot Wars (スーパーロボット大戦 Sūpā Robotto Taisen?, or Super Robot Taisen, abbreviated as SRW) is a series of tactical role-playing video games produced by Banpresto, a Japanese division of Namco Bandai. Its main feature is having a plot involving multiple mecha titles, allowing characters from different titles to team up or battle each other. The first game in the franchise was released for the Nintendo Game Boy in 1991 and later games are released on various consoles and handhelds. Currently, only 3 games see release outside of Japan.
All the games follow a basic structure: when a stage begins, the character receives introductory dialogue between playable characters, leading to the scenario on the battle field. To complete a scenario, the player must accomplish scenario objectives. Some scenarios are longer, with multi-part missions or have new objectives added as the story unfolds. On battle field, the player and enemy take turns to order their units with commands available, such as movement, attacking, forming squads and casting "Spirit Commands", a set of magic-like spells unique to each pilot. Once the scenario is cleared, more dialogue is exchanged between characters before the player is taken to an intermission menu. Here, units can be upgraded or optional parts installed, characters' stats and skills can be changed or upgraded, and other maintenance actions can be performed before the player continues on with the game.
Many games also have hidden features that can only be gained through a special sequence of events or completing optional challenging objectives. Some of these bonuses include extra stages, different endings, captured enemy machines and special upgrade for specific units, such as the IWSP Pack for the GAT-X105 Strike Gundam. In some games these are called "Skill Points" ("Battle Masteries" in the North American localizations) and the difficulty of the game increases accordingly.